General Fusion Hits 8.4 Million Degrees in Plasma Compression Milestone

The breakthrough represents a more than threefold increase in electron temperature, validating the company’s mechanical compression approach. By using a lithium liner to drive the plasma toward fusion conditions, General Fusion aims to bypass the capital-intensive infrastructure required by traditional tokamak or inertial-confinement models. The LM26 machine, which operates at roughly 50% of the diameter required for a commercial-scale plant, achieved these results in under two years of development.

Technical data submitted for peer review indicates the plasma remained stable during the compression phase, with researchers observing a tenfold increase in both plasma density and poloidal magnetic field. Tony Donné, chair of the company’s science advisory committee, noted that the alignment between experimental results and computer modelling provides a foundation for the machine’s next technical targets: 10 million degrees Celsius and the Lawson criterion. While these results do not constitute net energy gain, they serve as a critical validation for the firm’s engineering path.

This scientific progress occurs as General Fusion prepares for a potential public listing. The company has entered a business combination agreement with Spring Valley Acquisition Corp. III, a SPAC that would see the entity trade on the Nasdaq under the ticker GFUZ. Shareholders are scheduled to vote on the merger on July 6, 2026. If approved, the company will face the challenge of transitioning from a pre-revenue development firm to a publicly traded player in the global energy market.